Hi thanks for your advices, I'll try FAC/AFAC it's for my monitor (works on replica 1/w65c816sxb (emulation mode) and mostly works on commodore 8032) the idea is to have one moniteur for many machines I have 4 pointers PTR = $0054 SRC = $0002 DST = $00DD AUXPTR = $0000 PTR is a generic pointer to access memory (in low level functions) SRC/DST are used for transfers AUXPTR is used while loading/saving in hex format I'm planning to be able to build the monitor on the following machines: - w65c816sxb - replica 1 (Vince Briel) - micro kim (Vince Briel) - cbm 8032 - apple 2 - SYM 1 - Wichit 6502 trainer - cbm 8096 (monitor in ext64) - VIC 20 - C64 - PLUS 4 - CBM II - w65c02sxb - atari 800 - oric atmos - any other 6502 machine if I get enough information on zero page and binary format I'll put the code on github when I have reached a certain level of stability On 15/11/2019 10:14, Anders Carlsson wrote: > André Fachat wrote: > >> If you don't use floating points you could use the FAC and other float >> registers (IIRC they are in zp, right?) > > Yes, some possible locations with PET addresses (which are different > from VIC/C64): > > INDEX1: $1F - $20 (utility pointers) > INDEX2: $21 - $22 > TEMPF3: $4B - $4F (temporary FLPT storage) > TEMPF1: $54 - $58 > TEMPF2: $59 - $5D > FAC: $5E - $63 > AFAC: $66 - $6B > > As André wrote, it depends what the program does and which parts of > the ROM it uses. If it doesn't do anything with the FAC, there should > be plenty of space, in particular if you store the original ZP content > and restore it on exit. > > Best regards > > Anders Carlsson > > >Received on 2020-05-29 23:38:42
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